Experimental study of charging kinetics in Yttria Stabilized Zirconia

It is well known that the presence of space charge in an insulator is correlated with an electric breakdown. Many studies have been carried out on the experimental characterization of space charges. In our previous work, we have studied the difference in the charging kinetics between “trapper” insulator (pure spinel) and “conductive” one (Yttria Stabilized Zirconia (YSZ)) at low current density J0 of primary beam. This difference is attributed to the difference in conductivities. The main objective of this paper is to first review the charging effects occurring when a “conductive” material YSZ is subjected to electron irradiation at low J0, using a Scanning Electron Microscopy (SEM), and next to study the dependence of the charge-trapping phenomena in YSZ on the current density. The results show the existence of permanent current in the conductive material which is characterized by a steady state yield σ∞ which fixes the maximum value of J0 being withstood by a “conductive” material without charge accumulation beneath its surface.